I don't have a doctor, so email would go straight to a spam folder.
If I did had a doctor, I'd be surprised and all that, but, well, 15 minutes isn't all that much. So I'd probably write some last will and mention that I would prefer to be cremated. And then I'd run out of time and die.

I always get nostalgic feels from listening to the elywnn music. I could hear the crickets and the moon was out, just running through elwynn down to goldshire. So beautiful. I was checking out the tavern, loved the music. Then a night elf asked me to suck his cock for 15s.

Write my will and a long letter expressing my opinion about everything, who I like, dislike, whats wrong with the world, what should be done, what shows were great, which weren't, share my wisdom, tell the people I care about that I care about them, my thoughts about existence, the meaning of things etc.

Basically I would make it my legacy, so people can remember me by it, also I'd include my passwords and usernames to all my accounts, so that they can (for the first time) see what I was up to all the time I spend behind a pc.

Thinking about it...I'd call it:

title: "My Legacy"
subtitle: "<insert my name>, uncensored!"

Hope I'd finish it in time
And if I had time left, I'd spend it with someone I care about.

Signature infractions suck especially when they are just about the size of TEXT! WTB token limit!

I'd likely do a little "pbbtharharhar" laugh as I first began to read it... Then my face will start to melt with fear. Cry a little, eventually shrug it off, and around that time I will probably be dead.

Write a short will, give a few quick words of encouragement to my loved ones. Then I would close my eyes and meditate. I would calm myself and enter into death without fear and with a sound mind.

If Goku's power level increases at the same rate till the end of DBGT as it does till the end of the Frieza saga, as a SS4 Goku would have a PL of roughly 939 Quinoctogintillion. For reference that is a 260 digit number. A PL of 14,600 is required to destroy an earth sized planet. There are about 2 nonillion earths worth of mass in the universe. That means SS4 Goku can destroy the universe about 32 Octosexagintillion times over. There's a reason they made Goku a god at the end of GT.

*Looks outside at window* Damn, no clear sky to see the stars. Oh well, I still would pick my mp3 player and go outside, lay down on grass, play my favourite music and look at the dark sky while I think about my life. Then at the last few seconds I realise I forgot to delete embarrassing stuff from my computer. Whole neighbourhood will then hear my epic last roar: "NNNNNNNOOOOOOOOOOOOOOOOOOOOOOOOoooooooooooooooouu............"

Provided I'd believe that e-mail (a phone call would be more convincing:P) dedicate the 15m to get 15m more time and so on. First call 911. Since I'm perfectly healthy now, the tumor can't be that super. They might cut it out in time or it might not even become a problem in 15m at all so I might have more time. No doctor can tell the future.

Remember remember the fifth of November
Gunpowder, treason and plot.
I see no reason why gunpowder, treason
Should ever be forgot...